/* ====================================================
   shared base styles — color tokens, layout shell,
   header (brand + mode + theme toggles), footer.
   Loaded first; per-site styles.css overlays.
   ==================================================== */

:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-elev: #f6f7f9;
  --fg: #0d1117;
  --fg-muted: #57606a;
  --fg-subtle: #8b949e;
  --border: #d0d7de;
  --border-strong: #afb8c1;
  --accent: #0969da;
  --accent-fg: #ffffff;
  --warn: #9a6700;
  --warn-bg: #fff8c5;
  --warn-border: #d4a72c;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --r: 6px;
  --maxw: 880px;
}
:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0d1117;
  --bg-elev: #161b22;
  --fg: #e6edf3;
  --fg-muted: #9198a1;
  --fg-subtle: #6e7681;
  --border: #30363d;
  --border-strong: #484f58;
  --accent: #4493f8;
  --accent-fg: #0d1117;
  --warn: #d29922;
  --warn-bg: #2d2a14;
  --warn-border: #5a4a16;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d1117;
    --bg-elev: #161b22;
    --fg: #e6edf3;
    --fg-muted: #9198a1;
    --fg-subtle: #6e7681;
    --border: #30363d;
    --border-strong: #484f58;
    --accent: #4493f8;
    --accent-fg: #0d1117;
    --warn: #d29922;
    --warn-bg: #2d2a14;
    --warn-border: #5a4a16;
  }
}

/* ---------- Resets / base typography ---------- */

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scrollbar-gutter: stable; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

button:focus-visible,
a:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- Utilities ---------- */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  clip: rect(0 0 0 0);
  overflow: hidden;
  white-space: nowrap;
}
.mono { font-family: var(--mono); }
.muted { color: var(--fg-muted); }
.subtle { color: var(--fg-subtle); }

/* ---------- Header (brand + mode + theme) ---------- */

header.app-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
}
.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.brand {
  font-family: var(--mono);
  font-size: 15px;
  color: var(--fg-muted);
  text-decoration: none;
  white-space: nowrap;
}
.brand .b-br   { color: var(--fg-subtle); }
.brand .b-tag  { color: var(--fg); font-weight: 600; }
.brand .b-attr { color: var(--fg-muted); }
.brand .b-eq   { color: var(--fg-subtle); }
.brand .b-str  { color: var(--accent); }

.mode-toggle,
.theme-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
  background: var(--bg-elev);
}
.mode-toggle button,
.theme-toggle button {
  appearance: none;
  background: transparent;
  border: 0;
  color: var(--fg-muted);
  font: inherit;
  padding: 6px 12px;
  cursor: pointer;
  min-height: 36px;
}
.theme-toggle button {
  font-size: 13px;
  padding: 6px 10px;
}
.mode-toggle button[aria-pressed="true"],
.theme-toggle button[aria-pressed="true"] {
  background: var(--bg);
  color: var(--fg);
  box-shadow: inset 0 0 0 1px var(--border-strong);
}
.mode-toggle button + button,
.theme-toggle button + button {
  border-left: 1px solid var(--border);
}

.header-spacer { flex: 1; }
.icon-btn {
  appearance: none;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--fg-muted);
  border-radius: var(--r);
  padding: 6px 10px;
  font: inherit;
  cursor: pointer;
  min-height: 36px;
}
.icon-btn:hover { color: var(--fg); border-color: var(--border-strong); }

/* ---------- Main / footer ---------- */

main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 24px 16px 64px;
}

footer.app-footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 24px 16px 48px;
  color: var(--fg-subtle);
  font-size: 13px;
  line-height: 1.6;
}
footer.app-footer a { color: var(--fg-muted); }

.skeleton {
  color: var(--fg-subtle);
  font-family: var(--mono);
  font-size: 14px;
}

/* ---------- SSR intro (visible to crawlers & JS-off users) ---------- */

.ssr-intro h1 {
  font-size: 28px;
  font-weight: 600;
  line-height: 1.25;
  margin: 0 0 16px;
}
.ssr-intro h2 {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin: 28px 0 10px;
}
.ssr-intro p {
  line-height: 1.55;
  margin: 0 0 14px;
  color: var(--fg-muted);
  max-width: 65ch;
}
.ssr-intro ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.ssr-intro li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  line-height: 1.5;
}
.ssr-intro li:last-child { border-bottom: 0; }
.ssr-intro li strong { color: var(--fg); }
.ssr-intro code {
  background: var(--bg-elev);
  padding: 1px 5px;
  border-radius: 3px;
  font-size: 13px;
  font-family: var(--mono);
}
.ssr-intro noscript p {
  margin-top: 16px;
  padding: 12px 14px;
  border-left: 3px solid var(--warn-border);
  background: var(--warn-bg);
  border-radius: 0 var(--r) var(--r) 0;
  color: var(--fg);
}

/* ---------- Section heading style (reused by both sites) ---------- */

.detail-section { margin: 24px 0; }
.detail-section h2 {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin: 0 0 10px;
}
.detail-summary {
  font-size: 18px;
  line-height: 1.5;
  margin: 0 0 24px;
}

/* ---------- Generic copy button ---------- */

.copy-btn {
  appearance: none;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--fg-muted);
  border-radius: var(--r);
  padding: 6px 10px;
  font-family: var(--mono);
  font-size: 13px;
  cursor: pointer;
  min-height: 32px;
}
.copy-btn:hover { color: var(--fg); border-color: var(--border-strong); }
.copy-btn.copied { color: var(--accent); border-color: var(--accent); }

/* ---------- Mobile breakpoint for header ---------- */

@media (max-width: 540px) {
  .header-inner { padding: 10px 12px; gap: 8px; }
  .brand { font-size: 14px; }
  main { padding: 16px 12px 48px; }
}